SEO checklist done, but site still not showing up on Google

Question:
We made a site for a conference we’re running - I have completed all of the SEO checklist I can, outside of choosing a custom domain, but my site is still not showing up on Google

Product:
…not sure, think it’s just the Editor

What are you trying to achieve:
To get my site showing up on Google!

What have you already tried:
Completed SEO checklist, checked indexing on Google Search Console, read a bunch of online how-tos…but it seems like I’ve covered what I need to? Wix’s help files make it seem like the only way to get indexed is to have a custom domain?

Additional information:
Sorry if this is a rookie question, maybe I’m just looking in the wrong place!